Energy dissipation and self‐centering capacities of posttensioning precast segmental ultra‐high performance concrete bridge columns

Abstract

The research aims to better balance energy dissipation (ED) and self-centering capacities of posttensioning (PT) precast segmental ultra-high performance concrete bridge columns by adjusting common design parameters. A numerical model is established based on the equivalent plastic hinge model and validated by the cyclic loading test. The validated model is used to conduct a parametric study to investigate the effects of seven common design parameters on ED and self-centering capacities. The results show the proposed numerical model can accurately predict ED and self-centering capacities of the proposed bridge columns. The effect of the strength-yield ratio can be neglected when it is more than 1.2. The lower aspect ratio can first weaken and then improve the equivalent viscous damping ratio with drift ratio up, while the lower aspect ratio can reduce the residual drift ratio. With larger ED bar ratio, smaller unbonded length of ED bars and lower PT tendon ratio, the equivalent viscous damping ratio, and the residual drift ratio are significantly increased. It is not a perfect way to improve ED capacity by increasing the ED bar ratio, which can significantly magnify the residual drift ratio and limitedly enhance the equivalent viscous damping ratio, besides economical considering. Improving the gravity loading ratio and the initial PT stress are deemed to be effective ways to reduce the residual drift ratio because they not only have little influence on the equivalent viscous damping ratio but also result in no more costs. K E Y W O R D Sbridge columns, numerical model, parametric analysis, precast segmental construction, self-centering, ultra-high performance concrete

Seismic Design Method of Self‐Centring‐Segment Bridge Piers with Tensile‐Type Viscoelastic Dampers

“…(3) Estimating the equivalent viscous damping of the structural system:After installing the viscoelastic damper, the damper further provides additional damping to the structure. e nonlinear hysteretic damping of self-centring structures can be calculated by the hysteretic loop curve obtained from the nonlinear analysis of the structure [16] and the calculation method for the additional damping from viscoelastic dampers based on the method derived in the previous section. (4) Determining the effective viscous damping: e equivalent viscous damping ratio is the damping ratio corresponding to the precast-segment pier when the pier reaches the target displacement under the action of ground motion, but the horizontal displacement amplitude of the pier top is mostly smaller than the target displacement under the action of ground motion.…”

“…(8) Calculating the seismic inertial force corresponding to the target displacement:According to formula (16), the seismic inertial force generated by the target displacement is calculated as follows:…”

“…[15] proposed a methodology to calculate the shear strength of precast-segment concrete piers. Based on the geometric and material symmetry characteristics of precast-segment bridge piers, Wang et al [16,17] established an equivalent plastic hinge model of posttensioning precast-segment ultrahigh-performance concrete bridge columns and discussed the influences of seven related parameters on the energy dissipation and self-centring capacity of the piers. ey proposed a new quantitative design criterion for the selfcentring capacity of precast-segment ultra-high-performance concrete bridge piers and established a fine numerical model.…”

Parametric study on seismic performance of prefabricated bridge piers connected by ultra‐high performance concrete grout

“…Yang et al 16 presented quasi‐static tests on precast post‐tensioned (PT) concrete segmental column specimens with UHPC segment at the bottom and indicated that the specimens were typically nonemulative precast concrete pier and UHPC segment eliminated the damage near the rocking planes. Wang et al 18 conducted the analysis of energy dissipation and self‐centering capacities of PT precast segmental UHPC bridge columns based on the proposed equivalent plastic hinge finite element model, and several design guidelines were suggested. Shafieifar et al 19 proposed an innovative UHPC connection to connect precast column and cap beam in order to shift damage region, increase tolerances, and simplify reinforcement configuration.…”

Seismic performance analysis of self-centering segment piers with mortise-tenon shear connectors based on cyclic pseudo-static test

“…The balance between self-centering capacity and energy dissipation capacity is a highlighted issue. Zheng Wang et al [19] pointed out that the increase of the axial compression ratio and the initial pretension stress was an effective way to reduce the residual displacement. Cai Zhong Kui et al [20] proposed a method of using FRP bars as longitudinal bars to reduce the residual displacement after the earthquake.…”